This invention relates generally to typing systems and more particularly concerns printing characters in bold form in such systems.
One method of accomplishing the printing of characters in bold form in a typing system is to print a character, reposition the printhead or print element over the already-printed character, with the printhead shifted a small amount (such as 1/60 of an inch), and then to print the character a second time. This gives the typist the opportunity to emphasize certain words in a sequence of words by printing those emphasized words in bold form. Such a technique for producing text in bold form can be employed, for example, in an electronic typewriter or in a computer-based typing system operated under software control to drive a printer in a "key-to-print" mode.
In another type of system, a computer-based word processing system, text is arranged in a printable form on a display screen, and then sent to a printer for printing. In such systems, text designated as "bold" on the display screen (as selected during keying of the text by the operator), is printed in bold form when the page or pages of text from the word processor are printed. This bold printing is accomplished by printing a whole line of text twice in succession, with the second pass starting a small amount, such as 1/60 of an inch, offset from the first pass.
When a two-pass bold printing function is implemented in a typewriter system, or in a computer-based system operating software simulating a typewriter, it is important to the operator that the placement of text on paper be interactive. That is, it is important for the operator to see the keyed-in characters on paper in order to adequately determine if characters are properly placed on the paper. This is especially important when filling in forms.
Therefore, the approach taken in word processing systems, that of delaying the printing of bold text (typically with the text only visible on a display screen) and then printing an entire line in two passes, is not adequate for the needs of a typist.
As stated above, in present typewriter systems implementing the feature of printing in bold form, each character to be printed in bold form is printed twice as it is keyed. This approach, however, has the shortcoming that the printer quickly falls behind the typist, and the operator once again loses the ability to observe the results of the entry of keystrokes as they are entered.
It is the general objective of the present invention to provide printing in bold form, in typing systems such as have been described, which permits good interactivity for the operator.